This application relates to U.S. patent application entitled WRENCH ORIFICE WITH LATERAL GRIPPING GROOVES filed by the inventor herein, of which the application serial number and filing date are not known at the time of this filing.
The present invention relates to hand tools, particularly wrenches which have an orifice for turning fasteners, including sockets and box wrenches.
When turning a wrench on a fastener, users frequently encounter problems where the wrench slips off the fastener because the wrench has become tilted on the fastener during operation, and/or, the fastener head is eroded or manufactured with a tapered head. These problems are referred to herein as xe2x80x9ctilt-offxe2x80x9d and xe2x80x9ctaper-offxe2x80x9d effects.
More specifically, applicant defines the xe2x80x9ctilt-offxe2x80x9d effect as an effect which occurs when a user is turning a fastener (either tightening or loosening) and the wrench becomes slightly tilted on the fastener. When this occurs, the forces involved tend to push the wrench away from and off the fastener often damaging the fastener and/or wrench, and possibly injuring the user. Applicant defines the xe2x80x9ctaper-offxe2x80x9d effect as an effect which occurs when a user is turning a fastener (either tightening or loosening) which is slightly eroded, rusted, and/or manufactured with a slight tapered or conical head. When this occurs, the forces involved also tend to push the wrench away from and off the fastener often damaging the fastener and/or wrench, and possibly injuring the user. Applicant believes that the xe2x80x9ctilt-offxe2x80x9d and xe2x80x9ctaper-offxe2x80x9d effects defined herein occur easily and frequently because it is difficult for a user to maintain a continuous, properly seated relationship between a wrench and fastener when both are being forcibly turned. Additionally, it is common to encounter a fastener which is slightly eroded, rusted, and/or manufactured with the fastener head slightly tapered or conical.
In the past, there have been many attempts, some successful, to improve the lateral (side-to-side) turning interaction between a wrench and fastener. The prior art addresses the lateral friction between a wrench and fastener, not longitudinal friction. Whereas, lateral friction affects the side-to-side interaction between a wrench and a fastener, and, longitudinal friction affects the up and down or vertical interaction between a wrench and a fastener. The prior art, lateral friction technologies have little or no affect on reducing the effects of xe2x80x9ctilt-offxe2x80x9d and xe2x80x9ctaper-offxe2x80x9d as defined herein, in fact, they may actually promote the effects of tilt-off and taper-off.
Applicant recognizes that some prior art, lateral friction technologies include internal engaging surfaces that have grooves, however, the grooves are positioned longitudinally or generally parallel to the axis of wrench rotation. Accordingly, grooves positioned generally parallel to the axis of wrench rotation, actually reduce the longitudinal friction between a wrench and a fastener thereby promoting the affects of xe2x80x9ctilt-offxe2x80x9d and xe2x80x9ctaper-off,xe2x80x9d as defined herein. Accordingly, grooves positioned longitudinally (up and down) teach away from, and are in contradiction with, the structure and objectives of the present invention.
The present invention involves a wrench tool which has an orifice with a driving end for turning fasteners. The orifice is substantially cylindrical and comprises an array of longitudinal, engaging surfaces positioned therein forming a symmetrical pattern around an imaginary central axis. At least three of the longitudinal engaging surfaces each have at least a small region thereon roughened, and the roughened, internal engaging surfaces form a symmetrical pattern around the imaginary central axis. And, each roughened region is formed so as to enhance longitudinal friction between the wrench tool and the fasteners. In some preferred embodiments, there is a predetermined total number of longitudinal engaging surfaces, and the total number of longitudinal engaging surfaces is divisible by six using whole numbers.
Each roughened region promotes longitudinal friction between wrench and fastener thereby reducing the effects of xe2x80x9ctilt-offxe2x80x9d and/or xe2x80x9ctaper-offxe2x80x9d as defined herein. Importantly, this longitudinal friction technology may be used in conjunction with known lateral friction technologies to provide for a wrench tool with superior lateral and longitudinal gripping performance under torque. In fact, the longitudinal friction technology of the present invention is more effective when used in conjunction with lateral type friction technologies which enhance the surface-to-surface engagement between wrench and fastener.
Accordingly, it is an important objective of the present invention described above to increase the longitudinal or up-and-down friction between a turning wrench and a fastener thereby preventing or significantly reducing the effects of xe2x80x9ctilt-offxe2x80x9d and/or xe2x80x9ctaper-offxe2x80x9d as defined herein.
It is another objective of the present invention to reduce wrench wear and breakage.
It is yet another objective of the present invention to reduce the potential of injury to a user.
It is yet another objective of the present invention that it be compatible with other known lateral friction technologies so as to provide for a wrench tool with superior lateral and longitudinal gripping performance under torque.
And, it is yet another objective of the present invention that it be commercially viable, simple in design, and cost efficient to manufacture.